I've been a fan of Al Green's sweet soul music since he came out in the 70's but I just became aware of this documentary from the 80's and found out that the complete film is on YouTube so had to check it out. As the name would suggest, this story is based on Green's conversion to Jesus and his difficulty in reconciling his new found faith with his secular career.
The story is told via an interview with Al in a studio, along with interviews with his producer, as well as a then-current gospel show at an Air Force base, of all things. He's actually still great, with a funky gospel band, although, of course, he does not sing his old hits. He's very personable and charismatic in both the interviews and the concert, and they even show an entire (apparently) church service - which is at least as electrifying as his concert!
Any fan of soul music in general or Al in particular should definitely check it out!